1. Field of the Invention
The present invention relates to an outdoor unit having a housing that is vertically partitioned into a heat exchange chamber and a machine chamber through a partition plate, a heat exchanger and an air blower being mounted in the heat exchange chamber while a compressor and an electrical component box are mounted in the machine chamber.
2. Description of Related Art
In general, there is known an outdoor unit of an air conditioner in which a housing of the outdoor unit is vertically partitioned into a heat exchange chamber and a machine chamber through a partition plate, a heat exchanger and an air blower being mounted in the heat exchange chamber while a compressor and an electrical component box are mounted in the machine chamber.
For example, according to this type of outdoor unit proposed in JP-A-2009-30884, an electrical component box of the outdoor unit is designed so that a part thereof overhangs from the machine chamber to the heat exchanger chamber, and a heat sink of an electrical component unit is disposed at this overhang site. Outdoor air which is introduced from the back side of the machine chamber into the machine chamber by negative pressure of the air blower is introduced to the heat sink of the electrical component unit to cool the heat sink, and then the out air concerned is blown out to the heat exchanger.
A maintenance work is executed on this type of electrical component box while a front panel of the outdoor unit is detached. Therefore, for example when the electrical component box is equipped with a plate member which extends substantially straightly in the width direction of the machine chamber and an electrical component unit different from the electrical component unit described above is disposed on the front surface of the plate member, various kinds of works on the electrical component unit concerned can be easily performed from the front surface side. However, in this case, cooling air introduced from the back side of the machine chamber into the machine chamber hardly passes through the front surface side of the plate member, and thus there occurs such a situation that the electrical component unit disposed on the front surface of the plate member is not sufficiently cooled.
Furthermore, JP-A-2005-127691 discloses an outdoor unit in which an electrical component unit for supporting an electrical component board substantially in horizontal position is disposed at the upper portion of the partition plate for partitioning the housing into compartmented heat exchange chamber and machine chamber. In this type of outdoor unit, the electrical component unit comprises an electrical component case constructed by integrating a box-shaped box portion at the lower side and a planar board mount portion at the upper side, and a lid member for covering the electrical component board supported in the electrical component case, and the electrical component case is designed in a frame shape having a large opening, thereby enhancing ventilation, reducing materials, etc.
However, in the related arts, the strength of the electrical component case is lowered because of the electrical component case is designed in a frame shape, and thus when a load is applied from the outside through a top plate of the outdoor unit on the electrical component case below the top plate, the electrical case may be deformed, so that stress is applied to the electrical component board.